for the Atari 2600 video-game console,
by Warren Robinett.
The first action-adventure game.
The game introduced the idea of video-game items and a large multi-screen game world.
Adventure was the first action-adventure game. It was directly inspired by the original text-adventure game ("Collosal Cave") created by Willie Crowther and Don Woods during 1975-1978. The key idea of Atari Adventure was to adapt the text-adventure idea of a network of rooms (containing objects that could be moved around, and obstacles, and monsters) to the video-game medium.
The text-adventure medium used text to describe where you were in the game world, and what you were carrying, and the player typed text commands to do things in the game (to move around, pick up objects, and use the objects). Adapting this rooms-and-objects idea to the video game medium (which used graphics, movement, animation, sound, and a joystick input device) resulted in some pretty big changes to what kind of games you could make. This adaptation produced what we now call an "action-adventure game".
Adventure contained a number of video-game innovations. It introduced the idea of video-game items, which were small icon-like graphical objects which could be picked up by the player's avatar, and which functioned as tools to do things in the game world. (Examples are weapons, keys, magical items, and portals.) The game also introduced the possibility of a large multi-screen game world. Perhaps it may be hard to believe now, but up to that point, all video games had their action taking place within one single screen. (Think of Pong or Space Invaders or Pac-Man.) Adventure introduced the UI technique of the avatar moving off one of the four edges of the screen in to an "adjacent" room, thus opening up the possibility of moving through a large network of rooms. Adventure also contained sophisticated computer-controlled bad guys (three dragons and one bat), each of which was controlled by a certain set of prioritized "desires" and "fears". These simulated motivations produced interesting behaviors of the creatures in the game, particularly since they could interact with one another. Thus, Adventure introduced significant early innovations in algorithmically controlled entities (AI's) in video games.
The implementation of the game was challenging, since the entire program and its graphics data had to fit into the 4096 bytes (4K bytes) of ROM space available in the Atari 2600's ROM, and also into the 128 bytes (1/8 K) of RAM available in the 2600. The processor was also weak: an 8-bit processor (the 6502) with a 1.2 MHz clock rate. The reason I give for how I was able to fit the game into these tiny memory spaces is: "a good data structure, and efficient coding". My 2016 book "The Annotated Adventure" goes into more detail about the implementation of the game.
Adventure was both a commercial and critical success. It sold 1 million copies during 1979-1983 at $25 retail. Its user-interface conventions were widely imitated (for example, by Legend of Zelda, and many later games), and it thus founded the video-game genre of the action-adventure game.